Visma reconciliation silently crashing - credit invoices never marked paid

Production incident: invoice/credit customers (e.g. Tekno-Marine) could not complete purchases despite available credit. Root cause: the visma:reconciliation job had silently crashed on bad Visma payment data for over a year, so paid invoices were never marked PAID and CreditLimiter blocked new orders.

Bug chain fixed:

weekly -> daily schedule + null paymentMethod PHP crash (#553)
null card_type vs NOT NULL column (#582)
null external_id fetched ALL tenant payments, negative-amount unsigned overflow, no per-payment error isolation (#584)
closing-balance ignored fees, aborting later channels (#587)
daily reconciliation healthcheck with Sentry alert (#591)

Backfilled ~1118 invoices to PAID, releasing the credit backlog. Tekno-Marine's three registered invoices now PAID; credit freed.

Pull requests